This section provides background information related to the present disclosure which is not necessarily prior art.
In an attempt to reduce the quantity of NOx and particulate matter emitted to the atmosphere during internal combustion engine operation, a number of exhaust aftertreatment devices have been developed. A need for exhaust aftertreatment systems particularly arises when diesel combustion processes are implemented. Typical aftertreatment systems for diesel engine exhaust may include one or more of a diesel particulate filter (DPF), a selective catalytic reduction (SCR) system (including a urea injector), a hydrocarbon (HC) injector, and a diesel oxidation catalyst (DOC).
Although urea that converts to ammonia in the exhaust stream is useful for assisting in the reduction of NOx using SCR, the use of ammonia that is formed before being provided to the exhaust stream provides greater efficacy in reducing NOx. Further, the use of hydrogen can be useful for regenerating a DPF or other catalyst-coated substrates. It is desirable, therefore, to develop various systems and methods for generating ammonia and hydrogen for exhaust after-treatment.